1. Field of the Invention
The invention relates to a tool system comprising a holder and a cutting tool that has a tool cutter and a fixing part.
2. Related Prior Art
Known in the prior art are tool systems for metal machining that, acting in combination with a rotating drive spindle or a non-rotating machine support, constitute a rotating or non-rotating machining tool. For example, DE 34 48 086 C2 discloses a tool for internal machining. When combined with a machine tool that imparts a translational motion to the holder, such tool systems can also be used as a broaching tool.
Normally, such tool systems, preferably comprising a cutting tool composed of a hard metal material, are used for machining operations that are to be performed with high precision. In order to ensure conformity with correspondingly close tolerances and to achieve a high quality of the respectively machined workpiece surfaces, secure and rigid fastening of the cutting tool to the holder is of crucial importance, it being necessary to ensure that cutting forces acting upon the fixing part via the tool cutter do not result in deviations of the centering or positioning of the cutting tool. The known tool systems do not adequately fulfill this requirement. Since it is necessary for a projecting length beyond the holder to be provided for the tool cutter in order to enable chip-removing machining to be effected in regions located outside of the contour of the holder, the cutting force acts at a location in the system that projects relative to the holder, as a result of which there occur at the fixing part of the cutting tool forces and moments that impair rigid and secure fixing.
Accordingly, in order to avoid such disadvantages in the case of a tool system of the generic type, it has already been proposed, in the German utility model 299 11 894 U1, that the tool cutter, for the purpose of chip-removing machining, be left projecting beyond the holder of the tool system by a predefinable projecting length, the holder being provided, on its outer circumference, with a supporting part that projects in the direction of the projecting length of the tool cutter and constitutes a supporting surface for at least partial bearing contact of the cutting tool. In the case of the known solution, the holder has the shape of a shank that defines a longitudinal axis, said supporting part being constituted by a supporting body that projects radially, relative to the longitudinal axis, from the circumferential surface of the shank and is realized as a single piece with the latter, and the shank, in turn, constituting, at least at its free end, a recess as a seat for receiving a fixing part of the cutting tool, which recess is open at the end face of the shank and on the circumference of the shank. In the case of the known solution, cutting bodies, as cutting tools, are mounted in a distributed manner in various cutting planes and in a plurality of identically realized receivers of the holder, the respective cutting tool having full-surface support on a recess base, extending in the form of an arc or flute, as a seat in the holder for chip-removing machining. It is not possible in such a manner to preclude the occurrence of static redundancy in the fixing of the tool in the receiver, which could impair the machining accuracy. In addition, owing to the multiplicity of cutting tools used, a particularly stiff overall design of the tool system is almost unachievable with the special arcuate mounting provided for said cutting tools, which again can disadvantageously affect the machining accuracy.